US8282258B2 - Backlight module - Google Patents
Backlight module Download PDFInfo
- Publication number
- US8282258B2 US8282258B2 US12/757,345 US75734510A US8282258B2 US 8282258 B2 US8282258 B2 US 8282258B2 US 75734510 A US75734510 A US 75734510A US 8282258 B2 US8282258 B2 US 8282258B2
- Authority
- US
- United States
- Prior art keywords
- backlight module
- light
- reflective sheet
- disposed
- guide plate
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Fee Related, expires
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Classifications
-
- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
- G02B6/0001—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings specially adapted for lighting devices or systems
- G02B6/0011—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings specially adapted for lighting devices or systems the light guides being planar or of plate-like form
- G02B6/0033—Means for improving the coupling-out of light from the light guide
- G02B6/005—Means for improving the coupling-out of light from the light guide provided by one optical element, or plurality thereof, placed on the light output side of the light guide
- G02B6/0055—Reflecting element, sheet or layer
-
- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
- G02B6/0001—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings specially adapted for lighting devices or systems
- G02B6/0011—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings specially adapted for lighting devices or systems the light guides being planar or of plate-like form
- G02B6/0081—Mechanical or electrical aspects of the light guide and light source in the lighting device peculiar to the adaptation to planar light guides, e.g. concerning packaging
- G02B6/0086—Positioning aspects
- G02B6/0088—Positioning aspects of the light guide or other optical sheets in the package
Definitions
- the invention relates to a backlight module having reduced light halos and improved luminous uniformity.
- FIG. 1 shows a schematic diagram illustrating a conventional backlight module.
- the backlight module 100 under a liquid crystal panel 102 includes a top brightness enhancement film (BEF) 104 , a bottom brightness enhancement film 106 , a light diffusion film 108 , a light guide plate 110 and a reflective sheet 112 .
- BEF brightness enhancement film
- AA area active display area
- a light source 114 in the backlight module 100 becomes shorter and shorter.
- light halos are formed on the liquid crystal panel 102 to seriously reduce luminous uniformity.
- Such deficiency can not be cured by spreading light-diffusing dots.
- a light-absorption adhesive may be used to improve luminous uniformity, the fabrication cost and assembly complexity are increased and the brightness of the backlight module 100 is reduced.
- one object of the invention is to provide an a backlight module having reduced light halos and improved luminous uniformity.
- a backlight module includes a frame, a reflective sheet, a light guide plate, a light source, and an optical film set.
- the frame defines an accommodation space, and the reflective sheet is disposed in the accommodation space.
- the light guide plate is disposed in the accommodation space and on one surface of the reflective sheet.
- the light source is disposed on one side of the light guide plate, and the optical film set is disposed on another side of the light guide plate opposite the reflective sheet.
- the reflective sheet is hollowed out at a position overlapping the light source to form at least one opening so as to reduce light halos and improved luminous uniformity as a result, and the area of the opening is 0.25 to 2 times as much of a projection area on which the light source projects on the reflective sheet.
- a backlight module includes a positioning member, a light guide plate, a light source, and an optical film set.
- the positioning member defines an accommodation space, and the light guide plate is disposed in the accommodation space.
- the light source is disposed on one side of the light guide plate, and the optical film set is disposed on one side of the light guide plate and confined in the positioning member.
- the positioning member is hollowed out at a position overlapping the light source to form at least one opening so as to reduce light halos and improved luminous uniformity as a result.
- the area of each opening is 0.25 to 2 times as much of a projection area on which a corresponding light-emitting diode projects on the positioning member.
- the positioning member includes a frame and a back plate, the optical film set and the back plate are disposed on two opposite sides of the light guide plate, and the opening is formed on the frame or the back plate.
- FIG. 1 shows a schematic diagram illustrating a conventional backlight module.
- FIG. 2 shows an exploded diagram of a backlight module according to an embodiment of the invention.
- FIG. 3 shows an exploded diagram of a backlight module according to another embodiment of the invention.
- FIGS. 4A-4C show schematic diagrams illustrating different positions of openings.
- FIG. 5 shows a schematic diagram illustrating different shapes of openings.
- FIG. 6A shows a schematic diagram illustrating the brightness distribution of a conventional backlight module.
- FIG. 6B shows a schematic diagram illustrating the brightness distribution of a backlight module according to an embodiment of the invention.
- FIG. 7A shows the visual effect of FIG. 6A
- FIG. 7B shows the visual effect of FIG. 6B .
- FIG. 2 shows an exploded diagram of a backlight module according to an embodiment of the invention.
- a liquid crystal panel P is on the top of the backlight module 10 .
- the backlight module 10 includes a frame 12 , a light guide plate 14 , and an optical film set S.
- the optical film set S may include a light diffusion film 18 , an X-axis prismatic brightness enhancement film (BEF) 22 a , and a Y-axis prismatic BEF 22 b .
- the frame 12 defines an accommodation space M and has multiple notches 121 .
- Each optical film has a protrusion 122 formed at a position corresponding to a notch 121 .
- the optical film set S is confined in a horizontal plane of the frame 12 .
- a back plate 24 under the frame 12 cooperates with the frame 12 to fix each optical member, and a reflective sheet 26 is disposed under the accommodation space M of the frame 12 to reflect emitting light beams of light emitting diodes 28 .
- the light guide plate 14 is disposed in the accommodation space M and on one surface of the reflective sheet 26 .
- Multiple light emitting diodes 28 are arranged on one side of the light guide plate 14
- the optical film set S is disposed on one side of the light guide plate 14 opposite the reflective sheet 26 .
- the reflective sheet 26 is hollowed out at a position overlapping each light emitting diode 28 to form at least one opening 32 .
- the number of openings 32 may be identical to the number of the light emitting diodes 28 , but this is not limited. Though a larger area of each opening may more effectively reduce light halos and provide better visual effect, the possible decrease in the overall brightness should be also considered.
- the area of each opening 32 that corresponds to a light emitting diode 28 is preferably set as 0.25 to 2 times as much of a projection area on which the light emitting diode 28 projects on the reflective sheet 26 .
- FIG. 3 shows an exploded diagram of a backlight module according to another embodiment of the invention.
- the openings 32 are not limited to be formed on the reflective sheet 26 .
- a back plate 24 and an optical film set S are respectively disposed on two opposite sides of a light guide plate 14 .
- the openings 32 are formed on the back plate 24 instead of a reflective sheet 26 at a position overlapping the light emitting diodes 28 to similarly reduce light halos.
- optical films are confined in the frame 12 and the back plate 24 in this embodiment, this is not limited.
- optical films may be confined in a single member or a combination of other elements. As long as the member for positioning the optical films is hollowed out at a position overlapping the light emitting diodes 28 to form openings 32 , the light halos are allowed to be reduced.
- each opening 32 is not limited as long as it is corresponding to a light source.
- multiple openings 32 are parallel to a light source and arranged in a row along one side of a reflective sheet 26 .
- an opening is obliquely ( FIG. 4B ) or horizontally ( FIG. 4C ) formed on a corner of the reflective sheet 26 .
- the number and shape of openings 32 are not limited. For example, as shown in FIG.
- the opening 32 may be in the shape of a polygon, a circle, an ellipse, a semi-circle, a semi-ellipse, an arc plus a line segment, or a combination of at least two of them.
- FIG. 6A shows a schematic diagram illustrating the brightness distribution of a conventional backlight module 100 .
- FIG. 6B shows a schematic diagram illustrating the brightness distribution of a backlight module 10 according to an embodiment of the invention, where openings are formed on the reflective sheet 26 or the back plate 24 .
- FIG. 7A illustrates the visual effect of a backlight module without openings shown in FIG. 6A
- FIG. 7B illustrates the visual effect of a backlight module with openings shown in FIG. 6B . It can be clearly seen from these figures the light halos are obviously reduced to improve visual effect, according to the above embodiments of the invention.
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- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Optics & Photonics (AREA)
- Planar Illumination Modules (AREA)
Abstract
A backlight module includes a frame, a reflective sheet, a light guide plate, a light source, and an optical film set. The frame defines an accommodation space, and the reflective sheet is disposed in the accommodation space. The light guide plate is disposed in the accommodation space and on one surface of the reflective sheet. The optical film set is disposed one side of the light guide plate opposite the reflective sheet. The reflective sheet is hollowed out at a position overlapping the light source to form at least one opening so as to reduce light halos.
Description
(a) Field of the Invention
The invention relates to a backlight module having reduced light halos and improved luminous uniformity.
(b) Description of the Related Art
In light of the above-mentioned problem, one object of the invention is to provide an a backlight module having reduced light halos and improved luminous uniformity.
According to an embodiment of the invention, a backlight module includes a frame, a reflective sheet, a light guide plate, a light source, and an optical film set. The frame defines an accommodation space, and the reflective sheet is disposed in the accommodation space. The light guide plate is disposed in the accommodation space and on one surface of the reflective sheet. The light source is disposed on one side of the light guide plate, and the optical film set is disposed on another side of the light guide plate opposite the reflective sheet. The reflective sheet is hollowed out at a position overlapping the light source to form at least one opening so as to reduce light halos and improved luminous uniformity as a result, and the area of the opening is 0.25 to 2 times as much of a projection area on which the light source projects on the reflective sheet.
According to another embodiment of the invention, a backlight module includes a positioning member, a light guide plate, a light source, and an optical film set. The positioning member defines an accommodation space, and the light guide plate is disposed in the accommodation space. The light source is disposed on one side of the light guide plate, and the optical film set is disposed on one side of the light guide plate and confined in the positioning member. The positioning member is hollowed out at a position overlapping the light source to form at least one opening so as to reduce light halos and improved luminous uniformity as a result.
In one embodiment, the area of each opening is 0.25 to 2 times as much of a projection area on which a corresponding light-emitting diode projects on the positioning member. The positioning member includes a frame and a back plate, the optical film set and the back plate are disposed on two opposite sides of the light guide plate, and the opening is formed on the frame or the back plate.
Other objectives, features and advantages of the present invention will be further understood from the further technological features disclosed by the embodiments of the present invention wherein there are shown and described preferred embodiments of this invention, simply by way of illustration of modes best suited to carry out the invention.
The above and other technical content, characteristics, and effects of the invention will be described in details with reference to the drawings. For clarity, the wording related to direction, such as up, down, left, right, front, back, etc., is merely used to describe the direction with respect to the drawings but does not limit the scope of the invention.
Besides, the position of each opening 32 is not limited as long as it is corresponding to a light source. For example, as shown in FIG. 4A , multiple openings 32 are parallel to a light source and arranged in a row along one side of a reflective sheet 26. Alternatively, an opening is obliquely (FIG. 4B ) or horizontally (FIG. 4C ) formed on a corner of the reflective sheet 26. In addition, the number and shape of openings 32 are not limited. For example, as shown in FIG. 5 , the opening 32 may be in the shape of a polygon, a circle, an ellipse, a semi-circle, a semi-ellipse, an arc plus a line segment, or a combination of at least two of them.
Although the present invention has been fully described by the above embodiments, the embodiments should not constitute the limitation of the scope of the invention. Various modifications or changes can be made by those who are skilled in the art without deviating from the spirit of the invention. Any embodiment or claim of the present invention does not need to reach all the disclosed objects, advantages, and uniqueness of the invention. Besides, the abstract and the title are only used for assisting the search of the patent documentation and should not be construed as any limitation on the implementation range of the invention.
Claims (13)
1. A backlight module, comprising:
a frame for defining an accommodation space;
a reflective sheet disposed in the accommodation space of the frame;
a light guide plate disposed in the accommodation space and on one surface of the reflective sheet;
a light source disposed on one side of the light guide plate; and
an optical film set disposed on another side of the light guide plate opposite the reflective sheet;
wherein the reflective sheet is hollowed out at a position overlapping the light source to form at least one opening so as to reduce light halos, and the area of the opening is 0.25 to 2 times as much of a projection area on which the light source projects on the reflective sheet.
2. The backlight module as claimed in claim 1 , wherein the reflective sheet has multiple openings, the light source comprises multiple light emitting diodes, and the number of the openings is identical to the number of the light emitting diodes.
3. The backlight module as claimed in claim 1 , wherein the optical film set comprises at least one light diffusion film and at least one prismatic brightness enhancement film.
4. The backlight module as claimed in claim 1 , wherein the frame has at least one notch and the optical film set has at least one protrusion formed at a position corresponding to the notch.
5. The backlight module as claimed in claim 1 , wherein the opening is formed on a corner of the reflective sheet.
6. The backlight module as claimed in claim 1 , wherein the reflective sheet has a plurality of openings arranged in row along one side of the reflective sheet.
7. A backlight module, comprising:
a positioning member for defining an accommodation space;
a light guide plate disposed in the accommodation space;
a light source disposed on one side of the light guide plate; and
an optical film set disposed on one side of the light guide plate and confined in the positioning member;
wherein the positioning member is hollowed out at a position overlapping the light source to form at least one opening so as to reduce light halos.
8. The backlight module as claimed in claim 7 , wherein the positioning member comprises a frame and a back plate, the optical film set and the back plate are disposed on two opposite sides of the light guide plate, and the opening is formed on the frame.
9. The backlight module as claimed in claim 7 , wherein the positioning member comprises a frame and a back plate, the optical film set and the back plate are disposed on two opposite sides of the light guide plate, and the opening is formed on the back plate.
10. The backlight module as claimed in claim 7 , wherein the light source comprises multiple light emitting diodes, and the number of the openings is identical to the number of the light emitting diodes.
11. The backlight module as claimed in claim 10 , wherein the area of each opening is 0.25 to 2 times as much of a projection area on which a corresponding light-emitting diode projects on the positioning member.
12. The backlight module as claimed in claim 7 , wherein the optical film set comprises at least one light diffusion film and at least one prismatic brightness enhancement film.
13. The backlight module as claimed in claim 7 , wherein the positioning member has at least one notch and the optical film set has at least one protrusion formed at a position corresponding to the notch.
Applications Claiming Priority (6)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
TW98111763 | 2009-04-09 | ||
TW098111763 | 2009-04-09 | ||
TW98111763A | 2009-04-09 | ||
TW99108208A | 2010-03-19 | ||
TW099108208 | 2010-03-19 | ||
TW099108208A TWI416222B (en) | 2009-04-09 | 2010-03-19 | Backlight module |
Publications (2)
Publication Number | Publication Date |
---|---|
US20100259949A1 US20100259949A1 (en) | 2010-10-14 |
US8282258B2 true US8282258B2 (en) | 2012-10-09 |
Family
ID=42934254
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US12/757,345 Expired - Fee Related US8282258B2 (en) | 2009-04-09 | 2010-04-09 | Backlight module |
Country Status (2)
Country | Link |
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US (1) | US8282258B2 (en) |
TW (1) | TWI416222B (en) |
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20120154967A1 (en) * | 2010-12-15 | 2012-06-21 | Samsung Sdi Co., Ltd. | System for monitoring over voltage protection of battery pack and method thereof |
US11619776B2 (en) | 2018-12-12 | 2023-04-04 | E Ink Holdings Inc. | Light guide assembly and reflective display device |
Families Citing this family (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN103175033B (en) * | 2013-03-25 | 2015-11-25 | 南京中电熊猫液晶显示科技有限公司 | Side light source LED-backlit module |
US10088619B2 (en) * | 2013-04-08 | 2018-10-02 | Sakai Display Products Corporation | Reflection sheet, light source device and display apparatus |
CN104566038A (en) * | 2015-01-15 | 2015-04-29 | 京东方光科技有限公司 | Backlight source and display device |
KR101736932B1 (en) * | 2015-11-30 | 2017-05-17 | 엘지디스플레이 주식회사 | Liquid crystal display device |
CN107726142B (en) * | 2017-10-20 | 2020-05-19 | 友达光电(苏州)有限公司 | Backlight module and display device |
WO2023070266A1 (en) * | 2021-10-25 | 2023-05-04 | 瑞仪光电(苏州)有限公司 | Backlight module and display device |
Citations (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20040076396A1 (en) | 2001-02-14 | 2004-04-22 | Yoshinori Suga | Light guiding body, light reflective sheet, surface light source device and liquid crystal display device using the light reflective sheet, and method of manufacturing the light reflective sheet |
US20040257791A1 (en) * | 2003-06-18 | 2004-12-23 | Shih-Hsien Chen | Thin backlight module |
US20050254260A1 (en) * | 2004-05-13 | 2005-11-17 | Cheng-Wei Li | Light positioning device |
US20070002590A1 (en) * | 2005-06-30 | 2007-01-04 | Lg.Philips Lcd Co., Ltd. | Bottom frame for liquid crystal display device, backlight assembly and liquid crystal display device using the same |
-
2010
- 2010-03-19 TW TW099108208A patent/TWI416222B/en not_active IP Right Cessation
- 2010-04-09 US US12/757,345 patent/US8282258B2/en not_active Expired - Fee Related
Patent Citations (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20040076396A1 (en) | 2001-02-14 | 2004-04-22 | Yoshinori Suga | Light guiding body, light reflective sheet, surface light source device and liquid crystal display device using the light reflective sheet, and method of manufacturing the light reflective sheet |
US20040257791A1 (en) * | 2003-06-18 | 2004-12-23 | Shih-Hsien Chen | Thin backlight module |
US20050254260A1 (en) * | 2004-05-13 | 2005-11-17 | Cheng-Wei Li | Light positioning device |
US20070002590A1 (en) * | 2005-06-30 | 2007-01-04 | Lg.Philips Lcd Co., Ltd. | Bottom frame for liquid crystal display device, backlight assembly and liquid crystal display device using the same |
Cited By (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20120154967A1 (en) * | 2010-12-15 | 2012-06-21 | Samsung Sdi Co., Ltd. | System for monitoring over voltage protection of battery pack and method thereof |
US8643991B2 (en) * | 2010-12-15 | 2014-02-04 | Samsung Sdi Co., Ltd. | System for monitoring over voltage protection of battery pack and method thereof |
US11619776B2 (en) | 2018-12-12 | 2023-04-04 | E Ink Holdings Inc. | Light guide assembly and reflective display device |
Also Published As
Publication number | Publication date |
---|---|
TW201037421A (en) | 2010-10-16 |
US20100259949A1 (en) | 2010-10-14 |
TWI416222B (en) | 2013-11-21 |
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Legal Events
Date | Code | Title | Description |
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AS | Assignment |
Owner name: WINTEK CORPORATION, TAIWAN Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNORS:YE, ZHI-TING;YU, CHANG-WEI;YANG, NIEN-YING;AND OTHERS;SIGNING DATES FROM 20100329 TO 20100330;REEL/FRAME:024212/0124 |
|
REMI | Maintenance fee reminder mailed | ||
LAPS | Lapse for failure to pay maintenance fees | ||
STCH | Information on status: patent discontinuation |
Free format text: PATENT EXPIRED DUE TO NONPAYMENT OF MAINTENANCE FEES UNDER 37 CFR 1.362 |
|
FP | Expired due to failure to pay maintenance fee |
Effective date: 20161009 |